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Retatrutide

researchMetabolic/Weight
Evidence grade
DResearch/compounded/adjunct (no established FDA indication)
Cardiovascular · 0–5 · separate axis
1
Preparation guide · Retatrutide reconstitution →
In the shop · assay ↗
Read first · not dosing instructions

Educational and research reference only. Not medical advice, not a recommendation, and not dosing instructions for any person. Figures are reported from the cited source and may be wrong or out of date. Research peptides are not approved for human use. Adults 18+. Consult a licensed physician before any decision about your health.

PurposeMetabolic / Weight loss
MechanismTriple agonist (GLP-1/GIP/glucagon) to reduce weight and increase energy expenditure
EffectsLess hunger, slower digestion, better blood sugar; often improves BP and overall CV risk
DosingTrial doses (not approved): phase 2 (Jastreboff, NEJM 2023) arms of 1, 4, 8 or 12 mg once weekly — the 1 mg arm stayed at 1 mg, the others started at 2 or 4 mg with escalation every 4 weeks; phase 3 TRIUMPH-1 started at 2 mg and escalated every 4 weeks to 4, 9 or 12 mg once weekly.
Bottom linePopular in research/compounding; human safety/benefit not well-established.
Protocols · as published3 sourced
Clinical trialPhase 2 (Jastreboff, NEJM 2023)
RouteSubcutaneous injection
FrequencyOnce weekly, 48 weeks
StartingArms of 4 mg or more started at 2 mg or 4 mg; a 1 mg arm was fixed
EscalationGradual dose escalation every 4 weeks for up to 12 weeks
TargetArms: 1, 4, 8 or 12 mg once weekly. 48-week weight change -8.7% (1 mg) to -24.2% (12 mg) vs -2.1% placebo.
Maximum12 mg weekly (maximum studied)

GI events were dose-related and partially mitigated with a 2 mg rather than 4 mg start. Heart rate rose with dose, peaked at 24 weeks, then declined. Not approved.

Clinical trialPhase 3 TRIUMPH-1 (Lilly topline, 2026-05-21)
RouteSubcutaneous injection
FrequencyOnce weekly, 80 weeks
Starting2 mg
EscalationStarted at 2 mg once weekly, stepping up every 4 weeks to the target: 4 mg arm via one step at 2 mg; 9 mg arm via steps at 2, 4 and 6 mg; 12 mg arm via steps at 2, 4, 6 and 9 mg
Target4 mg, 9 mg or 12 mg once weekly. 80-week weight loss -19.0%, -25.9%, -28.3% vs -2.2% placebo.

Discontinuation for adverse events 4.1%, 6.9%, 11.3% (vs 4.9% placebo). Dysesthesia 12.5% at 12 mg. Company press release; peer-reviewed publication not yet checked.

Community protocol — not clinically establishedCommunity guide
RouteSubcutaneous injection
FrequencyOnce weekly
Starting2 mg weekly, weeks 1-4
Escalation4 mg weeks 5-8, 6 mg weeks 9-12, 9 mg weeks 13-16, 12 mg from week 17. The Lilly TRIUMPH-1 release lists the same 2, 4, 6 and 9 mg steps on the way to 12 mg.
Target4, 9 or 12 mg "depending on trial arm"
Cycle"Phase 3 studies ran 68-80 weeks"

Sold by grey-market vendors as "GLP-3". That is vendor slang, not a drug class.

Batches on file8
30 mgJA-102107 · 2026-0199.62%
60 mgJA-102108 · 2026-0199.71%
30 mgJA-68243 · 2025-0699.73%
20 mgJA-63070 · 2025-0499.49%
30 mgJA-63071 · 2025-0499.46%
10 mgJA-70680 · 2025-0799.42%
20 mgJA-70681 · 2025-0799.74%
10 mgJA-205040 · undatedno purity figure
Read with10
Cautions & interactions

Not FDA-approved; GI effects common in class; avoid self-administration

No well-established interaction profile for non-approved peptides; avoid combining multiple research compounds; discuss meds with clinician.

CV 1 of 5 — Limited direct cardiovascular evidence.